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Biomedical subjects

H Reckendorfer

Publications and source records attributed to H Reckendorfer.

At least 19 recordsLinked to original sources
PubMed1996

Intraperitoneal cholelithiasis after laparoscopic cholecystectomy--behavior of 'lost' concrements and their role in abscess formation.

UNLABELLED: In two experimental studies we sought preliminary information about the behavior of concrements lost in the peritoneal cavity during laparoscopic cholecystectomy. MATERIALS AND METHODS: In study 1, human gallstones were analyzed using X-ray diffraction, classified in three groups and examined with an ultramicroscope; then they were implanted in the peritoneal cavity of rats. After 8 weeks or 6 months, the animals were sacrificed and the concrements analyzed again as before. The tissues surrounding the calculi were also examined histologically. In study 2, human gallstones were examined with regard to bacterial contamination on the surface or in the middle of the calculi. The cholesterol content was analyzed, and the stones were divided into three groups and implantated in the rats as in the first study. After 8 weeks, the animals were sacrificed and areas with identifiable tissue reactions were examined histologically and microbiologically. RESULTS: The concrements lost their crystalline formation without any relation to their former cholesterol content, as shown by X-ray diffraction as well as ultramicroscopy. Mineralogically, these changes are a certain sign of structural dissolution. Cholesterol stones only caused abscess formations in association with gram-negative bowel germs. Sterile pigment concrements often led to a mesenchymal reaction such as granulomas. Contaminated pigment stones also resulted in extensive abscess formations.

Abscess↗
PubMed1995

Small bowel tissue high-energy phosphate regeneration after 7 hr of cold ischemic storage: comparison of University of Wisconsin and Eurocollins solutions.

As adenine nucleotide content has been shown to correlate with post-transplant function of livers and hearts, it was the aim of our study to investigate the regeneration of rat small bowel tissue high-energy phosphates after 7 hr of cold storage followed by incubation of everted small bowel sacs in normothermic oxygenated KHB for 1 hr. We compared the University of Wisconsin (UW) and the Eurocollins (EC) solutions. Krebs-Henseleit-bicarbonate buffer (KHB) was used to point out the effect of simple cold ischemic storage. After 7 hr of cold storage only small bowel stored in UW and EC solutions retained the capacity for almost total regeneration of ATP necessary for optimal posttransplant function, whereas in the KHB group we found only minimal regeneration. A similar pattern was found for the energy charge. These data support the superiority of UW and EC solutions over simple cold storage in KHB for preservation of small bowel.

Adenosine↗
PubMed1994

Administration of atracurium during reperfusion of rat livers after 21 h of cold ischaemic storage in different solutions.

The pharmacokinetics of atracurium are not altered by impaired hepatic function. The drug is therefore used widely in liver transplant patients. In previous work on the hepatotoxic effects of atracurium in an isolated, perfused rat liver model, we could not detect biochemical (release of lactate dehydrogenase or aspartate aminotransferase) or histological evidence of liver cell damage, except a reduction in hepatic tissue ATP content. In the present study, rat livers were reperfused with Krebs-Henseleit bicarbonate buffer with or without atracurium after 21 h of cold ischaemic storage in University of Wisconsin (UW), Bretschneider's HTK or Euro-Collins solution. UW-protected livers showed a complete restoration of ATP, total adenine nucleotides and energy charge during reperfusion, but the addition of atracurium diminished the regeneration capacity to about 50%. The energy charge (an index for determination of liver viability) was also reduced markedly.

Adenine Nucleotides↗
PubMed1994

Influence of incubated atracurium on rat liver function.

Degradation of atracurium by Hofmann elimination and ester hydrolysis depends mainly on pH and temperature and is said to be independent of liver and kidney function. Consequently atracurium is used widely in patients with liver failure. However, there is evidence that incubation of atracurium at 37 degrees C and pH 8 leads to leakage of LDH from hepatocyte cell cultures. We have tested the hepatotoxic effects of incubated atracurium in an isolated perfused rat liver model. After equilibration, atracurium 2010 mumol ml-1 (preincubated at pH 8 and 37 degrees C for 120 min) was administered over a period of 10 min followed by perfusion of Krebs-Henseleit bicarbonate buffer for 60 min. We found that incubation resulted in considerable degradation of atracurium and formation of laudanosine. Administration of incubated atracurium did not produce either biochemical or morphological damage to liver cells, but caused considerable increase in bile flow. We conclude that administration of preincubated atracurium did not produce impairment of liver cell function. The increase in bile flow could be beneficial if it occurs clinically.

Animals↗
PubMed1993

Proton spin-lattice relaxation time as liver transplantation graft viability parameter.

In this study proton NMR T1 of stored rat liver grafts was investigated and correlated with other viability parameters. Five different storage solutions were used and T1 as well as overall tissue water content, bile flow, and energy charge were determined after various periods of cold storage (1 to 48 hr). A good correlation between T1 and tissue water content was detected, suggesting the possible use of this relaxation time parameter as liver graft viability parameter in a combined protocol of rapid viability assays for human liver transplantation surgery.

Adenosine↗
PubMed1993

Proton spin-spin relaxation times as liver transplantation graft viability parameter.

In this study, spin-spin relaxation time T2 of stored rat liver grafts was investigated and correlated with other viability parameters. Five different storage solutions were applied and T2 as well as overall tissue water content, bile flow, and energy charge were determined for increasing durations of cold storage (1-48 hr). Good correlation between T2 and tissue water content was detected. In a subset of experiments, dealing with additional warm ischemia after cold storage, the relative increase of T2 and energy charge showed a very good correlation. The results suggest the possible use of relaxation time parameters as liver graft viability parameters in a combined protocol of rapid viability assays for human liver transplantation surgery.

Animals↗
PubMed1992

Comparison of HTK- and UW-solution for liver preservation tested in an orthotopic liver transplantation model in the pig.

The aim of this experimental study was to compare the preservation potency of University of Wisconsin (UW) and HTK (Bretschneider) solutions in an orthotopic liver transplantation (OLT) model in pigs. Livers were harvested using an in situ perfusion technique, where organs were flushed with the solution being tested, stored on ice--cold storage (CS)--for 2 or 24 h and then transplanted. Parameters monitored were liver enzymes in serum, hepatic water content, high energy phosphates, nuclear magnetic resonance (NMR) relaxation time T2, light microscopy and bile production. CS for 24 h is an extreme in pig liver preservation and is not compatible with animal survival. Biopsies showed drastic morphological changes and grafts did not produce bile in either group. (Bile production 2 h CS: HTK, 5.6 +/- 1.8 ml/h; UW, 4.7 +/- 2.3 ml/h) Enzyme release after reperfusion (deltaSGOT, deltaLDH) was higher in long-term preservation. Hepatic tissue water content significantly decreased during CS in UW preserved livers. Edema alter reperfusion (deltaH2O: HTK 24 h = +5.6%, UW 24 h = +4.8%) and regeneration capacity after reperfusion (UW 2 h = 63%, HTK 2 h = 55%, UW 24 h = 30%, HTK 24 h = 30%) were not significantly different. However, we did not observe major differences in preservation potency between the solutions tested. Differences were correlated, rather, with length 9 time of CS, than with the solution used. Therefore, HTK solution seemed to be a low potassium containing alternative to UW solution.

Adenosine↗
PubMed1992

Hepatotoxicity testing of atracurium and laudanosine in the isolated, perfused rat liver.

The pharmacokinetics of atracurium, which is degraded by Hofmann decomposition and ester hydrolysis, is not altered by impaired liver function. Atracurium should, therefore, be ideal for patients with heptic failure, and is now widely used in clinical practice. However, some studies reported considerable hepatotoxicity after atracurium, especially from its breakdown products--for example, leakage of lactate dehydrogenase (LDH) from isolated rat hepatocytes. Therefore, we have studied, in an isolated perfused rat liver model, biochemical and morphological changes after administration of either atracurium or its main metabolite, laudanosine. Despite using extremely high concentrations of these substances, we could not detect, biochemically (release of LDH or aspartate amino-transferase (AST)) or histologically, any signs of liver cell damage.

Animals↗
PubMed1992

Cold-preserved rat liver viability testing by proton nuclear magnetic resonance relaxometry.

The results of a series of experiments in the cold-preserved rat liver, applying a newly developed method of pretransplant viability testing, are described. The livers were stored either under simple hypothermic conditions (KHB) or in EC, HTK, or UW preservation solution. Livers were stored up to 48 hr and reperfused after a period of hypothermic storage of 1, 7, 14, or 21 hr. In a parallel series of experiments, with livers stored under identical conditions, repeated proton relaxometry measurements (0, 1, 7, 14, 24, 32, 48 hr) were undertaken; and ATP, ADP, AMP (Atkinson's energy charge), and water content of livers, as well as pH of storage solution, were estimated. Based on a strong correlation between proton spin-spin relaxation time T2 and tissue water content (edema), this new method may be useful to estimate the amount of cell swelling during hypothermic storage from a surgical biopsy of about 200 mg within a few minutes. There was, however, no significant correlation found between energy charge and/or pH and water content, T2, or bile flow. Our method could be useful as a rapid test method in experimental cold liver storage models and may be of interest in human liver transplantation as a viability indicator in combination with other parameters.

Animals↗
PubMed1992

Small bowel tissue high-energy phosphate alterations during hypothermic storage using different protecting solutions.

Since posttransplant function is closely related to energy status after the storage period, the aim of our study was to determine high-energy phosphates in rat small bowels after 21 h of simple ischemic cold storage using different storage solutions. We compared Eurocollins-solution, Bretschneiders-HTK-solution and a modified University of Wisconsin-solution. After flushing the small bowel both intravascularly and intraluminally with the protecting solution, segments of rat small bowel were stored in the same solution at 4 degrees C for 21 h. Determination of high-energy phosphates by high-performance liquid chromatography were done at indicated times. We found that small bowel stored in Eurocollins-solution produced the best graft viability after 21 h of cold storage by maintaining a sufficient level of high-energy phosphates. The high ATP levels were produced by the pronounced anaerobic glycolysis which was facilitated by the high concentration of glucose in the Eurocollins-solution.

Adenosine↗
PubMed1992

Hepatic energy metabolism during hypothermic storage and reperfusion using different protecting solutions.

Effects of 5 cold storage solution on hepatic high energy phosphate metabolism and metabolic function were examined using the isolated perfused rat liver. University of Wisconsin (UW), Euro-Collins (EC), and 2 cardioplegic solutions, Bretschneider's HTK and St. Thomas Hospital solution, were studied for their protective capacity. Krebs-Henseleit bicarbonate buffer (KHB) was used to point out the effect of simple hypothermia. Liver ATP, total adenine nucleotides and energy charge losses were significantly lower during 21 h of storage in UW-preserved livers. Also, only UW-protected livers were able to complete regeneration of ATP and total adenine nucleotides after 1 h of reperfusion, whereas EC, HTK, St. Thomas and KHB stored livers only showed minimal regeneration. Concerning metabolic function, UW protected livers liberated significantly less LDH and sGOT as well in the 21-hour storage solution as into the perfusate under reperfusion conditions. This study demonstrates the capability of UW solution in liver preservation by its ability to maintain and restore high energy phosphates.

Adenine Nucleotides↗